Optical filter and display device including the same

ABSTRACT

An optical filter includes a substrate including a plurality of pixel areas spaced apart from each other and a light-blocking area between the plurality of pixel areas, a plurality of color filters arranged on a first surface of the substrate and corresponding to the plurality of pixel areas, and a plurality of conversion layers arranged on the first surface of the substrate and corresponding to the plurality of color filters. Each of the conversion layers includes inclined side surfaces. The optical filter further includes a reflective layer on the inclined side surfaces of each of the plurality of conversion layers. The reflective layer extends to the light-blocking area and is arranged consecutively on two adjacent inclined side surfaces from among the inclined side surfaces of the plurality of conversion layers and the light-blocking area between the two adjacent inclined side surfaces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/725,090 filed Dec. 23, 2019, which claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2019-0002406, filed on Jan. 8,2019 in the Korean Intellectual Property Office, the disclosures ofwhich is incorporated by reference herein in their entirety.

TECHNICAL FIELD

Exemplary embodiments of the present inventive concept relate to anoptical filter and a display device including the same.

DISCUSSION OF THE RELATED ART

In accordance with advancements in various types of electronicapparatuses such as, for example, a cellular phone, a personal digitalassistant (PDA), a computer, a large TV, etc., various types of displaydevices that may be applied to the electronic apparatuses are beingdeveloped. For example, display devices widely used in the marketinclude a liquid-crystal display device including a backlight unit, anorganic light-emitting display device emitting light of different colorsin each pixel area, etc. Currently, a display device including a quantumdot-color conversion layer (QD-CCL) is being developed. Quantum dots areexcited by incident light to thereby emit light having a longerwavelength than that of the incident light. Light in a low-wavelengthband may be primarily used as the incident light.

SUMMARY

Color reproducibility and light-emitting efficiency of a display deviceincluding a quantum dot-color conversion layer (QD-CCL) may be improvedby improving light conversion efficiency of quantum dots. Exemplaryembodiments of the present inventive concept include an optical filterconfigured to increase utilization of incident light, by decreasingincident light that may not excite quantum dots (e.g., as a result ofbeing filtered out), and a display device including the optical filter.However, exemplary embodiments of the present inventive concept are notlimited thereto.

According to an exemplary embodiment, an optical filter includes asubstrate including a plurality of pixel areas spaced apart from eachother and a light-blocking area arranged between the plurality of pixelareas, a plurality of color filters arranged on a first surface of thesubstrate and corresponding to the plurality of pixel areas, and aplurality of conversion layers arranged on the first surface of thesubstrate and corresponding to the plurality of color filters. Each ofthe conversion layers includes at least one inclined side surface. Theoptical filter further includes a reflective layer arranged on the atleast one inclined side surface of each of the plurality of conversionlayers. The reflective layer extends to the light-blocking area and isarranged consecutively on two adjacent inclined side surfaces from amongthe inclined side surfaces of the plurality of conversion layers and thelight-blocking area between the two adjacent inclined side surfaces.

In an exemplary embodiment, a horizontal cross-sectional area of atleast one of the plurality of conversion layers decreases in a directionaway from the substrate.

In an exemplary embodiment, the color filters are spaced apart from eachother, and the reflective layer extends to a portion between twoneighboring color filters from among the plurality of color filters.

In an exemplary embodiment, the reflective layer is arranged betweenside surfaces of the two neighboring color filters.

In an exemplary embodiment, the plurality of color filters extends tothe light-blocking area such that side surfaces of the plurality ofcolor filters are in contact with each other.

In an exemplary embodiment, the plurality of color filters includes afirst color filter, a second color filter, and a third color filter.Each of the color filters transmits light of a different color. Thefirst color filter, the second color filter, and the third color filteroverlap each other in the light-blocking area to form a partition wall.

In an exemplary embodiment, the partition wall includes an inclinedsurface, and the plurality of conversion layers is arranged in concaveportions defined by the partition wall.

In an exemplary embodiment, the reflective layer covers an upper surfaceof the partition wall.

In an exemplary embodiment, the optical filter further includes aplanarization layer providing a flat surface by covering the pluralityof conversion layers.

In an exemplary embodiment, the plurality of conversion layers includesa first conversion layer, a second conversion layer, and a thirdconversion layer. Each of the conversion layers includes scatteringparticles. The first conversion layer further includes first quantumdots, and the second conversion layer further includes second quantumdots. The first quantum dots and the second quantum dots include a samematerial and have different sizes.

According to an exemplary embodiment, a display device includes alight-emitting panel configured to emit incident light of a singlecolor, and an optical filter configured to convert the incident lightinto light of different colors. The optical filter includes a substrateincluding a plurality of pixel areas spaced apart from each other and alight-blocking area arranged between the plurality of pixel areas, and aplurality of color filters arranged on a first surface of the substrateand corresponding to the plurality of pixel areas, in which the firstsurface of the substrate faces the light-emitting panel. The opticalfilter further includes a plurality of conversion layers arranged on thefirst surface of the substrate and corresponding to the plurality ofcolor filters, in which the incident light is incident on the pluralityof conversion layers, and a reflective layer arranged on side surfacesof the plurality of conversion layers. The reflective layer extends tothe light-blocking area and is arranged integrally on the side surfacesof the plurality of conversion layers and in the light-blocking areabetween the plurality of conversion layers.

In an exemplary embodiment, the light-emitting panel includes aplurality of light-emitting devices configured to generate the incidentlight of a single color. The light-emitting devices are arranged tocorrespond to the plurality of pixel areas.

In an exemplary embodiment, the light-emitting panel includes aliquid-crystal layer including a plurality of liquid-crystal molecules,and the optical filter further includes a planarization layer providinga flat surface by covering the plurality of conversion layers. Thedisplay device further includes a polarization layer arranged betweenthe light-emitting panel and the planarization layer.

In an exemplary embodiment, each of the plurality of conversion layersincludes an inclined side surface, and horizontal cross-sectional areasof the plurality of conversion layers decrease in a direction away fromthe substrate.

In an exemplary embodiment, the color filters are spaced apart from eachother, and the reflective layer is arranged between side surfaces of twoneighboring color filters from among the plurality of color filters inthe light-blocking area.

In an exemplary embodiment, the plurality of color filters includes afirst color filter, a second color filter, and a third color filter.Each of the color filters transmits light of a different color. Thefirst color filter, the second color filter, and the third color filteroverlap each other in the light-blocking area to form a partition wall.The plurality of conversion layers is arranged in a concave portiondefined by the partition wall.

In an exemplary embodiment, the reflective layer covers an upper surfaceof the partition wall, and the upper surface of the partition wall facesthe light-emitting panel.

In an exemplary embodiment, the plurality of conversion layers includesa first conversion layer, a second conversion layer, and a thirdconversion layer. Each of the conversion layers includes scatteringparticles. The first conversion layer further includes first quantumdots, and the second conversion layer further includes second quantumdots. The first quantum dots and the second quantum dots include a samematerial and have different sizes.

In an exemplary embodiment, colors of light that passes through thefirst conversion layer, the second conversion layer, and the thirdconversion layer are different from each other, and the color of thelight that passes through the third conversion layer is identical to acolor of the incident light.

In an exemplary embodiment, the display device further includes a lowrefractive index layer arranged between the plurality of color filtersand the plurality of conversion layers, and having a refractive indexequal to or less than about 1.2.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present inventive concept willbecome more apparent by describing in detail exemplary embodimentsthereof with reference to the accompanying drawings, in which:

FIG. 1 is a schematic plan view illustrating an example of a displaydevice according to an exemplary embodiment.

FIG. 2 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1 according to an exemplary embodiment.

FIG. 3 is an enlarged cross-sectional view of first to third conversionlayers of FIG. 2.

FIG. 4 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1 according to an exemplary embodiment.

FIG. 5 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1 according to an exemplary embodiment.

FIG. 6 is a schematic cross-sectional view illustrating a light-emittingpanel in the display device of FIG. 1 according to an exemplaryembodiment.

FIG. 7 is an equivalent circuit diagram of a pixel of the light-emittingpanel of FIG. 6.

FIG. 8 is a schematic cross-sectional view illustrating a light-emittingpanel in the display device of FIG. 1 according to an exemplaryembodiment.

DETAILED DESCRIPTION

Exemplary embodiments of the present inventive concept will be describedmore fully hereinafter with reference to the accompanying drawings. Likereference numerals may refer to like elements throughout theaccompanying drawings. Expressions such as “at least one of”, whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

It will be understood that although the terms “first”, “second”, etc.may be used herein to describe various components, these componentsshould not be limited by these terms. These components are only used todistinguish one component from another. Thus, a “first” component in anexemplary embodiment may be described as a “second” component in anotherexemplary embodiment.

As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be understood that when a layer, region, or component isreferred to as being “formed on” another layer, region, or component, itcan be directly or indirectly formed on the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may or may not be present.

When a certain exemplary embodiment may be implemented differently, aspecific process order may be performed differently from the describedorder. For example, two consecutively described processes may beperformed substantially at the same time or performed in an orderopposite to the described order.

FIG. 1 is a schematic plan view illustrating an example of a displaydevice 10 according to an exemplary embodiment. FIG. 2 is a schematiccross-sectional view taken along line II-II′ of FIG. 1 according to anexemplary embodiment. FIG. 3 is an enlarged cross-sectional view offirst to third conversion layers 150, 160, and 170 of FIG. 2.

Referring to FIGS. 1 to 3, according to an exemplary embodiment, thedisplay device 10 may include an optical filter 100 and a light-emittingpanel 200.

The optical filter 100 may receive incident light Lib generated from thelight-emitting panel 200, and emit light of first to third colors. In anexemplary embodiment, the incident light Lib incident from thelight-emitting panel 200 on the optical filter 100 may be light of asingle color, and light of the first to third colors emitted from theoptical filter 100 may be red light, green light, and blue light,respectively. The optical filter 100 may be directly adhered to thelight-emitting panel 200 by, for example, an adhesive layer. In anexemplary embodiment, an insulating layer or a filling layer may befurther included between the optical filter 100 and the light-emittingpanel 200. The insulating layer may include a transparent materialhaving transmissibility, and the filling layer may include an air layer.

The optical filter 100 may include a substrate 110, first to third colorfilters 130 a, 130 b, and 130 c arranged on a first surface of thesubstrate 110, first to third conversion layers 150, 160, and 170arranged in correspondence with the first to third color filters 130 a,130 b, and 130 c, respectively, and a reflective layer 190 arranged atleast on side surfaces of the first to third conversion layers 150, 160,and 170. The first surface of the substrate 110 refers to a surfacefacing the light-emitting panel 200.

The substrate 110 includes a pixel area PA and a light-blocking area BA.The pixel area PA is an area from which light is emitted and which issurrounded by the light-blocking area BA. The pixel area PA may bedivided into a first pixel area PA1, a second area PA2, and a thirdpixel area PA3, according to a color of the emitted light. The firstpixel area PA1, the second pixel area PA2, and the third pixel area PA3may be spaced apart from each other. The light-blocking area BA may belocated between adjacent areas from among the first pixel area PA1, thesecond pixel area PA2, and the third pixel area PA3.

The light-blocking area BA is an area from which light is not emitted,and may surround the first to third pixel areas PA1, PA2, and PA3. Asshown in FIG. 1, in an exemplary embodiment, the light-blocking area BAmay have a mesh form. However, the arrangement of each of the pixelareas PA1, PA2, and PA3 shown in FIG. 1 is exemplary, and the presentinventive concept is not limited thereto. For example, the first tothird pixel areas PA1, PA2, and PA3 may be arranged in various formsother than the form illustrated in FIG. 1.

The substrate 110 may include a material having transmissibility suchas, for example, an insulating material such as glass, plastic, crystal,etc. A material of the substrate 110 may be selected by taking intoaccount, for example, a mechanical strength, thermal stability,transparency, surface smoothness, ease of handling, waterproofness, etc.In an exemplary embodiment, when the substrate 110 includes a polymermaterial, the substrate 110 may include, for example, polycarbonate(PC), polyethylene terephthalate (PET), polyethylene (PE), polypropylene(PP), polysulfone (PSF), polymethyl methacrylate (PMMA), cellulosetriacetate (TAC), cyclo olefin polymer (COP), cyclic olefin copolymer(COC), etc.

The first to third color filters 130 a, 130 b, and 130 c include a dyeor a pigment to thereby transmit only a particular color. For example,the first color filter 130 a may selectively transmit only light of afirst color, the second color filter 130 b may selectively transmit onlylight of a second color, and the third color filter 130 c mayselectively transmit only light of a third color. In an exemplaryembodiment, light of the first color may be red light, light of thesecond color may be green light, and light of the third color may beblue light. The red light may be light having a peak wavelength equal toor greater than about 580 nm and less than about 750 nm. The green lightmay be light having a peak wavelength equal to or greater than about 495nm and less than about 580 nm. The blue light may be light having a peakwavelength equal to or greater than about 400 nm and less than about 495nm. The incident light Lib may be the light of the third color, that is,the blue light.

The term “about” as used herein is inclusive of the stated value andmeans within an acceptable range of deviation for the particular valueas determined by one of ordinary skill in the art, considering themeasurement in question and the error associated with measurement of theparticular quantity (i.e., the limitations of the measurement system).For example, “about” may mean within one or more standard deviations asunderstood by one of the ordinary skill in the art.

The first color filter 130 a may be arranged to correspond to at leastthe third pixel area PA3, the second color filter 130 b may be arrangedto correspond to at least the second pixel area PA2, and the third colorfilter 130 c may be arranged to correspond to at least the first pixelarea PAL For example, the first color filter 130 a may be arranged inthe third pixel area PA3 and not in the first and second pixel areas PA1and PA2, the second color filter 130 b may be arranged in the secondpixel area PA2 and not in the first and third pixel areas PA1 and PA3,and the third color filter 130 c may be arranged in the first pixel areaPA1 and not in the second and third pixel areas PA2 and PA3.

The first to third conversion layers 150, 160, and 170 may be arrangedon the first surface of the substrate 110 to correspond to the first,second, and third color filters 130 a, 130 b, and 130 c, respectively.For example, the first conversion layer 150 may be arranged in the thirdpixel area PA3 with the first color filter 130 a, the second conversionlayer 160 may be arranged in the second pixel area PA2 with the secondcolor filter 130 b, and the third conversion layer 170 may be arrangedin the first pixel area PA1 with the third color filter 130 c. When theincident light Lib is generated from the light-emitting panel 200, thefirst to third conversion layers 150, 160, and 170 convert the incidentlight Lib generated from the light-emitting panel 200 into light havinga particular color, and emit the light having the particular colortoward the substrate 110.

In an exemplary embodiment, the first conversion layer 150 may convertthe incident light Lib that is blue light into light Lr of the firstcolor. The light Lr of the first color may be red light. To do so, thefirst conversion layer 150 may include a first photosensitive polymer151 in which first quantum dots 152 are dispersed.

The first photosensitive polymer 151 may be an organic material havinglight transmissibility such as, for example, silicon resin, epoxy resin,etc.

The first quantum dots 152 may be excited by the blue incident light Libto thereby isotropically emit the light Lr of the first color having awavelength longer than that of the blue light. The first quantum dots152 may include, for example, a Group II-VI compound, a Group III-Vcompound, a Group IV-VI compound, a Group IV compound, or a combinationthereof.

First scattering particles 153 may be further dispersed in the firstphotosensitive polymer 151. The first scattering particles 153 mayscatter part of the blue incident light Lib, that is, the part which wasnot absorbed into the first quantum dots 152, so that a greater numberof the first quantum dots 152 are excited. As a result, a colorconversion rate of the first conversion layer 150 may be increased. Thefirst scattering particles 153 may include, for example, titaniumdioxide (TiO₂), metal particles, etc.

The second conversion layer 160 converts the blue incident light Libinto light Lg of the second color. The light Lg of the second color maybe green light. The second conversion layer 160 may include a secondphotosensitive polymer 161 in which second quantum dots 162 aredispersed. In the second photosensitive polymer 161, second scatteringparticles 163 may be dispersed with the second quantum dots 162. As aresult, a color conversion rate of the second conversion layer 160 maybe increased.

The second photosensitive polymer 161 may include a same material asthat of the first photosensitive polymer 151. The second scatteringparticles 163 may include a same material as that of the firstscattering particles 153. The second quantum dots 162 may include, forexample, a Group II-VI compound, a Group III-V compound, a Group IV-VIcompound, a Group IV compound, or a combination thereof. That is, thesecond quantum dots 162 may be a same material as that of the firstquantum dots 152. However, a size of the second quantum dots 162 may bedifferent than a size of the first quantum dots 152. For example, in anexemplary embodiment, a size of the second quantum dots 162 may be lessthan a size of the first quantum dots 152. Thus, the second quantum dots162 may be excited by the blue incident light Lib to therebyisotropically emit the light Lg of the second color having a wavelengthlonger than that of the blue light but shorter than that of the light Lrof the first color.

The third conversion layer 170 may include a third photosensitivepolymer 171 in which third scattering particles 173 are dispersed. Thatis, the third conversion layer 170 does not include a separate quantumdot that may be excited by the blue incident light Lib Like the firstand second photosensitive polymers 151 and 161, the third photosensitivepolymer 171 may include an organic material having lighttransmissibility. The third scattering particles 173 may include a samematerial as that of the first and second scattering particles 153 and163. Accordingly, since the blue incident light Lib incident on thethird conversion layer 170 may pass through the third conversion layer170 without a color change, the light Lb of the third color emittedthrough the third conversion layer 170 may be blue light. However, theblue incident light Lib may be scattered by the third scatteringparticles 173 in the third conversion layer 170, and then, emittedtoward the substrate 110.

The first to third conversion layers 150, 160, and 170 may be covered bya barrier layer 180. The barrier layer 180 may be arranged on the entirefirst surface of the substrate 110 to cover the first to thirdconversion layers 150, 160, and 170. For example, the barrier layer 180may cover an entirety of each of the first to third conversion layers150, 160, and 170. The barrier layer 180 includes an inorganicinsulating material such as, for example, silicon nitride (SiNx) and/orsilicon oxide (SiOx), and may prevent outgassing of the first to thirdconversion layers 150, 160, and 170.

Each of the first to third conversion layers 150, 160, and 170 may haveat least one inclined side surface. The at least one inclined sidesurface may be inclined toward a center of the corresponding conversionlayer in a cross-sectional view. In an exemplary embodiment, each sidesurface of each of the first to third conversion layers 150, 160, and170 may be inclined. In addition, since the reflective layer 190 isarranged over the inclined surface of each of the first to thirdconversion layers 150, 160, and 170, conversion efficiency of the firstquantum dots 152 and the second quantum dots 162 and light-emittingefficiency of the display device 10 may be improved.

The reflective layer 190 may be arranged directly on the barrier layer180. The barrier layer 180 may include a metal material having excellentreflectivity such as, for example, silver (Ag), aluminum (Al), etc. Thereflective layer 190 may have reflectivity equal to or greater thanabout 30%, for example, reflectivity equal to or greater than about 50%and less than about 100%. The reflective layer 190 may extend to thelight blocking area BA, and may be disposed in the light blocking areaBA. The reflective layer 190 reflects the incident light Lib, which didnot excite the first quantum dots 152 or the second quantum dots 162, tothereby reduce the incident light Lib that did not excite the firstquantum dots 152 or the second quantum dots 162 (e.g., the incidentlight Lib that is filtered out). Thus, utilization of the incident lightLib may be improved (e.g., less incident light Lib is wasted).Accordingly, the conversion efficiency of the first quantum dots 152 andthe second quantum dots 162 may be improved.

In addition, as shown in FIG. 2, the inclined side surface of each ofthe first to third conversion layers 150, 160, and 170 may be configuredso that horizontal cross-sectional areas of the first to thirdconversion layers 150, 160, and 170 decrease in a direction away fromthe substrate 110. For example, the horizontal cross-sectional area ofeach of the first to third conversion layers 150, 160, and 170 maydecrease as the distance from the substrate 110 increases. Thus, whenlight emitted from the first quantum dots 152 and the second quantumdots 162 and light scattered by the third scattering particles 173 arereflected by the reflective layer 190, the reflected light may proceedtoward the substrate 110. Accordingly, light-emitting efficiency of thedisplay device 10 may be improved. For example, an inclination angle ofthe inclined side surface of each of the first to third conversionlayers 150, 160, and 170 may be about 30° to about 85°.

The reflective layer 190 may extend to the light-blocking area BA. Forexample, a portion of the reflective layer 190 may be disposed in thefirst to third pixel areas PA1, PA2, and PA3, and the reflective layer190 may extend therefrom into the light-blocking area BA. The reflectivelayer 190 arranged in the light-blocking area BA may prevent light frombeing emitted to the outside through the light-blocking area BA andleaking from the display device 10. The reflective layer 190 may bearranged consecutively to correspond to two adjacent side surfaces amongside surfaces of the first to third color filters 130 a, 130 b, and 130c, in which the light-blocking area BA is arranged between the twoadjacent side surfaces. That is, the reflective layer 190 may bearranged integrally over the side surfaces of the first to third colorfilters 130 a, 130 b, and 130 c and in the light-blocking area BA. Forexample, the reflective layer 190 may be arranged in the light-blockingarea BA on two adjacent inclined side surfaces among inclined sidesurfaces of the first to third color filters 130 a, 130 b, and 130 c,and may extend continuously (e.g., without any breaks or openings)across the two adjacent inclined side surfaces and the correspondinglight-blocking area BA in which the reflective layer 190 is arranged. Inexemplary embodiments, the reflective layer 190 is not arranged onbottom surfaces of the first to third color filters 130 a, 130 b, and130 c. Thus, according to exemplary embodiments of the present inventiveconcept, since a separate light-blocking member is not needed to preventlight leakage, a structure of the optical filter 100 may be simplified.

As shown in FIG. 3, the first to third color filters 130 a, 130 b, and130 c may be spaced apart from each other, and the reflective layer 190may extend to neighboring portions between the first to third colorfilters 130 a, 130 b, and 130 c. For example, in an exemplaryembodiment, a concave portion 182 is located between the second colorfilter 130 b and the third color filter 130 c adjacent to each other.Since the reflective layer 190 is arranged in the concave portion 182,the reflective layer 190 is arranged between a side surface of thesecond color filter 130 b and a side surface of the third color filter130 c facing each other. Accordingly, when light is emitted via thesecond color filter 130 b and the third color filter 130 c, mixing ofcolors of the light may be prevented or reduced. Thus, a color matchingrate and color reproducibility of the display device 10 may be improved.

A low refractive index layer 140 may be further arranged between thefirst to third color filters 130 a, 130 b, and 130 c and the first tothird conversion layers 150, 160, and 170. The low refractive indexlayer 140 may include an inorganic material or an organic material. Thatis, the low refractive index layer 140 may be arranged over the firstsurface of the substrate 110, on which the first to third color filters130 a, 130 b, and 130 c are arranged, and may cover the first to thirdcolor filters 130 a, 130 b, and 130 c.

The low refractive index layer 140 may improve light-emitting efficiencyof light having passed through the first to third conversion layers 150,160, and 170. A refractive index of the low refractive index layer 140may be less than that of the first to third conversion layers 150, 160,and 170 and that of the first to third color filters 130 a, 130 b, and130 c. Thus, light-emitting efficiency of the light that passed throughthe first to third conversion layers 150, 160, and 170 may be improved.For example, the first to third conversion layers 150, 160, and 170 andthe first to third color filters 130 a, 130 b, and 130 c may have, forexample, a refractive index equal to or greater than about 1.4, forexample, a refractive index of about 1.4 to about 1.7. In this case, arefractive index of the low refractive index layer 140 may be less thanabout 1.4, for example, equal to or less than about 1.2.

Since the first to third conversion layers 150, 160, and 170 are spacedapart from each other, the low refractive index layer 140 may bedirectly in contact with the barrier layer 180 in the light-blockingarea BA. That is, the first to third conversion layers 150, 160, and 170may each have a form capsulized by the low refractive index layer 140and the barrier layer 180. For example, each of the first to thirdconversion layers 150, 160, and 170 may have boundaries defined by thelow refractive index layer 140 and the barrier layer 180. For example,each of the first to third conversion layers 150, 160, and 170 may havean upper boundary defined by the low-refractive index layer 140, andside boundaries and a lower boundary defined by the barrier layer 180.

The optical filter 100 may further include a planarization layer 120covering the first to third conversion layers 150, 160, and 170, therebyproviding a flat surface onto surfaces of the first to third conversionlayers 150, 160, and 170 facing the light-emitting panel 200. Theplanarization layer 120 may include a transparent organic material suchas, for example, polyimide resin, acrylic resin, a resist material, etc.The planarization layer 120 may be formed by using a wet process such asa slit-coating method, a spin coating method, etc., a dry process suchas a chemical vapor deposition method, a vacuum deposition method, etc.or the like.

FIG. 4 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1 according to an exemplary embodiment. For convenience ofexplanation, a further description of elements and technical aspectspreviously described may be omitted.

Referring to FIG. 4, the display device 10 may include thelight-emitting panel 200 configured to emit the blue incident light Lib,and the optical filter 100 configured to receive the incident light Liband emit light of first to third colors.

The optical filter 100 may include the substrate 110 including the firstto third pixel areas PA1, PA2, and PA3 and the light-blocking area BA,the first to third color filters 130 a, 130 b, and 130 c arranged on afirst surface of the substrate 110, the first to third conversion layers150, 160, and 170 arranged to correspond to the first to third colorfilters 130 a, 130 b, and 130 c, respectively, and the reflective layer190 arranged at least on side surfaces of the first to third conversionlayers 150, 160, and 170. The first surface of the substrate 110 refersto a surface facing the light-emitting panel 200.

In addition, the low refractive index layer 140 may be further arrangedbetween the first to third color filters 130 a, 130 b, and 130 c and thefirst to third conversion layers 150, 160, and 170. The first to thirdconversion layers 150, 160, and 170 may be covered by the barrier layer180, and the planarization layer 120 covers the first to thirdconversion layers 150, 160, and 170, thereby providing a flat surface tothe optical filter 100, as described with reference to FIGS. 1 to 3.

Referring to FIG. 4, the first to third color filters 130 a, 130 b, and130 c extend to the light-blocking area BA between adjacent areas fromthe first to third pixel areas PA1, PA2, and PA3, such that sidesurfaces of the first to third color filters 130 a, 130 b, and 130 cadjacent to each other are in contact with each other. For example, sidesurfaces of the first to third color filters 130 a, 130 b, and 130 cadjacent to each other may directly contact each other. Since sizes ofthe first to third color filters 130 a, 130 b, and 130 c are greaterthan those of the first to third pixel areas PA1, PA2, and PA3, evenwhen an error occurs in a position in which the first to third colorfilters 130 a, 130 b, and 130 c are arranged, a defect does not occur inthe optical filter 100. Thus, manufacture efficiency of the opticalfilter 100 may be improved.

In addition, thicknesses of the first to third color filters 130 a, 130b, and 130 c may be identical to each other. In this case, the sidesurfaces of the first to third color filters 130 a, 130 b, and 130 c maybe in contact with each other to thereby constitute a substantially flatsurface. Herein, when a surface is referred to as being substantiallyflat, it is to be understood that the surface is exactly flat, or if notexactly flat, is approximately flat within a measurement error as wouldbe understood by a person having ordinary skill in the art. Since thesurface formed by the first to third color filters 130 a, 130 b, and 130c is substantially flat, a subsequent process in which the lowrefractive index layer 140, the barrier layer 180, and the reflectivelayer 190 are formed over the first to third color filters 130 a, 130 b,and 130 c may be efficiently performed.

Each of the first to third conversion layers 150, 160, and 170 may havean inclined side surface, and the reflective layer 190 is arranged overthe inclined surfaces of each of the first to third conversion layers150, 160, and 170. For example, each of the first to third conversionlayers 150, 160, and 170 may have a side surface inclined toward acenter of the corresponding conversion layer. Thus, conversionefficiency of the first quantum dots 152 and the second quantum dots 162(see FIG. 3) and light-emitting efficiency of the display device 10 maybe improved. In addition, since the reflective layer 190 is extended tothe light-blocking area BA, the reflective layer 190 may prevent lightfrom being emitted to outside (e.g., outside of the display device 10)through the light-blocking area BA. Thus, light leaking from the displaydevice 10 may be prevented or reduced. Accordingly, according toexemplary embodiments of the present inventive concept, since a separatelight-blocking member is not needed to prevent light leakage, astructure of the optical filter 100 may be simplified.

FIG. 5 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1 according to an exemplary embodiment. For convenience ofexplanation, a further description of elements and technical aspectspreviously described may be omitted.

Referring to FIG. 5, the display device 10 may include the opticalfilter 100 and the light-emitting panel 200.

The optical filter 100 may include the substrate 110 including the firstto third pixel areas PA1, PA2, and PA3 and the light-blocking area BA,the first to third color filters 130 a, 130 b, and 130 c arranged on afirst surface of the substrate 110, first to third conversion layers 150a, 150 b, and 150 c arranged to correspond to the first to third colorfilters 130 a, 130 b, and 130 c, respectively, and the reflective layer190 arranged at least on side surfaces of the first to third conversionlayers 150 a, 150 b, and 150 c. The first surface of the substrate 110refers to a surface facing the light-emitting panel 200.

The first to third color filters 130 a, 130 b, and 130 c may overlapwith each other in the light-blocking area BA. The first to third colorfilters 130 a, 130 b, and 130 c may each transmit light of a particularcolor, for example, only red light, only green light, or only bluelight, respectively. When the first to third color filters 130 a, 130 b,and 130 c are stacked, the stacked first to third color filters 130 a,130 b, and 130 c may function as a black matrix that obstructs light.

Accordingly, when the first to third color filters 130 a, 130 b, and 130c overlap with each other in the light-blocking area BA, light may beprevented from being emitted to the outside (e.g., outside of thedisplay device 10) through the light-blocking area BA. Thus, lightleaking from the display device 10 may be prevented or reduced.

In addition, the first to third color filters 130 a, 130 b, and 130 coverlapping in the light-blocking area BA constitute a partition wall132 defining an area in which the first to third conversion layers 150a, 150 b, and 150 c are arranged. The first to third conversion layers150 a, 150 b, and 150 c may be formed in a concave portion, defined bythe partition wall 132, by using an inkjet method. Even though a methodof forming the first to third conversion layers 150 a, 150 b, and 150 cis different from that of the first to third conversion layers 150, 160,and 170 described with reference to FIG. 2, a function of the first tothird conversion layers 150 a, 150 b, and 150 c may be the same as thatof the first to third conversion layers 150, 160, and 170. Accordingly,the first to third conversion layers 150 a, 150 b, and 150 c may convertlight incident from the light-emitting panel 200 into light of aparticular color, and emit the light of the particular color toward thesubstrate 110.

In such a case that the partition wall 132 is constituted when the firstto third color filters 130 a, 130 b, and 130 c overlap each other in thelight-blocking area BA, the partition wall 132 has an inclinationsurface, and the reflective layer 190 may be arranged on the inclinedsurface of the partition wall 132. For example, when a horizontalcross-sectional area of the partition wall 132 becomes further away fromthe substrate 110, the inclined surface of the partition wall 132 maydecrease. In this case, the reflective layer 190 may be arranged on afirst surface of the partition wall 132 to thereby cover thelight-blocking area BA. Here, the first surface of the partition wall132 is a surface facing the light-emitting panel 200 that is a displaypanel, and may be referred to as an upper surface of the partition wall132. In such a case that the reflective layer 190 is arranged on thefirst surface of the partition wall 132, when light generated from thelight-emitting panel 200 proceeds toward the partition wall 312, thelight is reflected by the reflective layer 190 and directed toward thelight-emitting panel 200. The light reflected toward the light-emittingpanel 200 may be re-reflected by the light-emitting panel 200, forexample, by an opposite electrode 235 (shown in FIG. 6), and bere-incident onto the optical filter 100. Thus, utilization of incidentlight may be improved.

As described above, when the partition wall 132 has the inclinedsurface, the first to third conversion layers 150 a, 150 b, and 150 c,each in the concave portion between partition walls 132, may haveinclined surfaces. As a result, the reflective layer 190 is arranged onthe inclined surfaces of the first to third conversion layers 150 a, 150b, and 150 c. When light generated from the light-emitting panel 200 isreflected by the reflective layer 190, the reflective layer 190 maydirect light toward central portions of the first to third conversionlayers 150 a, 150 b, and 150 c. Thus, utilization of incident light maybe improved, and light conversion efficiency of the optical filter 100may be improved.

The planarization layer 120 may be arranged over the partition wall 132and the first to third conversion layers 150 a, 150 b, and 150 c. Theplanarization layer 120 may cover the partition wall 132 and the firstto third conversion layers 150 a, 150 b, and 150 c, thereby providing asubstantially flat surface.

The low refractive index layer 140 may be arranged on the first to thirdcolor filters 130 a, 130 b, and 130 c. The low refractive index layer140 may improve light-emitting efficiency of light having passed throughthe first to third conversion layers 150 a, 150 b, and 150 c. Inaddition, the barrier layer 180 may be arranged on the low refractiveindex layer 140. The barrier layer 180 may prevent outgassing of thefirst to third color filters 130 a, 130 b, and 130 c. The barrier layer180 may include an inorganic material. For example, the barrier layer180 may include an inorganic insulating material such as silicon nitride(SiNx) and/or silicon oxide (SiOx). Alternately, the barrier layer 180may include an organic insulating material, or an inorganic insulatinglayer and an organic insulating layer.

FIG. 6 is a schematic cross-sectional view illustrating a light-emittingpanel 200 in the display device 10 of FIG. 1 according to an exemplaryembodiment. FIG. 7 is an equivalent circuit diagram of a pixel of thelight-emitting panel 200 of FIG. 6.

Referring to FIGS. 6 and 7, the light-emitting panel 200 may includefirst to third pixels PX1, PX2, and PX3. The first pixel PX1 includes alight-emitting device 230 and a first pixel circuit 220 a configured tocontrol the light-emitting device 230. The second pixel PX2 includes thelight-emitting device 230 and a second pixel circuit 220 b configured tocontrol the light-emitting device 230. The third pixel PX3 includes thelight-emitting device 230 and a third pixel circuit 220 c configured tocontrol the light-emitting device 230.

The light-emitting device 230 may emit light of a third color, forexample, the blue light Lb, in which an amount of the emitted light iscontrolled by each of the first to third pixel circuits 220 a, 220 b,and 220 c. The light-emitting device 230 is arranged to correspond tothe pixel area PA (shown in FIG. 1) of the optical filter 100 (shown inFIG. 2). The blue light Lb emitted from the light-emitting device 230 isthe incident light Lib (shown in FIG. 2) incident on the optical filter100 (shown in FIG. 2).

For example, when an amount of the light Lb of the third color iscontrolled by the first pixel circuit 220 a of the first pixel PX1 andthe light Lb of the third color is emitted from the light-emittingdevice 230, the light Lb of the third color is converted into light of afirst color via the first conversion layer 150 (shown in FIG. 2) and thelight of the first color is emitted to the outside via the substrate 110(shown in FIG. 2). When an amount of the light Lb of the third color iscontrolled by the second pixel circuit 220 b of the second pixel PX2 andthe light Lb of the third color is emitted from the light-emittingdevice 230, the light Lb of the third color is converted into light of asecond color via the second conversion layer 160 (shown in FIG. 2) andthe light of the second color is emitted to the outside via thesubstrate 110 (shown in FIG. 2). In addition, when an amount of thelight Lb of the third color is controlled by the third pixel circuit 220c of the third pixel PX3 and the light Lb of the third color is emittedfrom the light-emitting device 230, the light Lb of the third color isemitted to the outside via the substrate 110 (shown in FIG. 2) withoutany color conversion via the third conversion layer 170. Accordingly,because the blue light Lb emitted from the light-emitting panel 200 isincident on the optical filter (shown in FIG. 2) and converted into redlight, green light, and blue light, a color image is displayed as animage of the blue light Lb.

Each of the first to third pixel circuits 220 a, 220 b, and 220 c isarranged in a pixel circuit layer 220 below the light-emitting device230. In an exemplary embodiment, each of the first to third pixelcircuits 220 a, 220 b, and 220 c may at least partially overlap thelight-emitting device 230. In an exemplary embodiment, each of the firstto third pixel circuits 220 a, 220 b, and 220 c or does not overlap thelight-emitting device 230.

As shown in FIG. 7, each of the first to third pixel circuits 220 a, 220b, and 220 c may include first and second thin-film transistors T1 andT2, a storage capacitor Cst, and wires electrically connected to thefirst and second thin-film transistors T1 and T2 and the storagecapacitor Cst. However, it is to be understood that the configurationshown in FIG. 7 is exemplary, and the first to third pixel circuits 220a, 220 b, and 220 c may have various configurations different than theconfiguration shown in FIG. 7. FIG. 7 may correspond to any of the firstto third pixel circuits 220 a, 220 b, and 220 c. In FIG. 7, the pixelcircuit is denoted by PC.

The second thin-film transistor T2 is a switching thin-film transistor,and connected to a scan line SL and a data line DL. According to aswitching voltage input from the scan line SL, the second thin-filmtransistor T2 may transmit a data voltage to the first thin-filmtransistor T1 when the data voltage is input from the data line DL. Thestorage capacitor Cst is connected to the second thin-film transistor T2and a driving voltage line PL. The storage capacitor Cst may store avoltage corresponding to a difference between a voltage transmitted fromthe second thin-film transistor T2 and a first power voltage ELVDDsupplied to the driving voltage PL. The first thin-film transistor T1 isa driving thin-film transistor, and connected to the driving voltageline PL and the storage capacitor Cst. The first thin-film transistor T1may control a driving current flowing from the driving voltage line PLto the light-emitting device 230 in correspondence with a value of thevoltage stored in the storage capacitor Cst.

The light-emitting device 230 may emit light having a certain brightnessaccording to the driving current. The light-emitting device 230 mayinclude a pixel electrode 231, an intermediate layer 233, and anopposite electrode 235. The opposite electrode 235 of the light-emittingdevice 230 may receive a second power voltage ELVSS. As an example, thelight-emitting device 230 may be an organic light-emitting diode.However, the light-emitting device 230 is not limited thereto.

The pixel electrode 231 may be electrically connected to a sourceelectrode or a drain electrode of a thin-film transistor. The pixelelectrode 231 is exposed through an opening of a pixel-defining layer237, and edges of the pixel electrode 231 may be covered by thepixel-defining layer 237.

The intermediate layer 233 may be arranged on the pixel electrode 231exposed through the pixel-defining layer 237. The intermediate layer 233may include an organic emissive layer. The organic emissive layer maybe, for example, a low-molecular weight organic material or a polymerorganic material. The intermediate layer 233 may selectively furtherinclude functional layers such as, for example, a hole transport layer(HTL), a hole injection layer (HIL), an electron transport layer (ETL),an electron injection layer (EIL), etc., in addition to the organicemissive layer.

The opposite electrode 235 may be arranged to cover the intermediatelayer 233 and the pixel-defining layer 237. The opposite electrode 235may be, for example, a transparent or translucent electrode. Forexample, the opposite electrode 235 may include a metal thin film havinga low work function. The opposite electrode 235 may include atransparent conductive layer including, for example, transparentconductive oxide (TCO).

An encapsulation layer 240 may be arranged on the light-emitting device230. The encapsulation layer 240 may cover the opposite electrode 235and be arranged over a whole surface of a base substrate 210. Theencapsulation layer 240 may include an inorganic encapsulation layerincluding at least one inorganic material, and an organic encapsulationlayer including at least one organic material. In an exemplaryembodiment, the encapsulation layer 240 may have a structure in which afirst inorganic encapsulation layer, an organic encapsulation layer, anda second inorganic encapsulation layer are stacked.

FIG. 8 is a schematic cross-sectional view illustrating thelight-emitting panel 200 in the display device of FIG. 1 according to anexemplary embodiment.

As described above with reference to FIG. 7, light generated from thelight-emitting panel 200 of FIG. 8 is blue light incident onto theoptical filter 100 of FIG. 2.

Referring to FIG. 8, the light-emitting panel 200 may include a firstsubstrate 211, a liquid-crystal layer 203 arranged over the firstsubstrate 211 and including a plurality of liquid-crystal molecules 213,and a pixel electrode PE and a common electrode CE, each applying anelectric field to the liquid-crystal layer 203. In addition, thelight-emitting panel 200 may include a second substrate 212 facing thefirst substrate 211.

A thin-film transistor (TFT) array layer, the pixel electrode PE, and afirst alignment layer AL1 may be arranged over the first substrate 211.

The first substrate 211 may be a glass substrate, or a plastic substrateincluding, for example, PET, polyethylene naphthalate (PEN), polyimide,etc.

The TFT array layer includes a switching device TFT, and includes aplurality of gate lines and a plurality of data lines. The switchingdevice TFT is a thin-film transistor, and includes an active layer AT, agate electrode GE, a source electrode SE, and a drain electrode DE.

A first insulating layer L1, which is a gate insulating layer, isarranged on the gate electrode GE. The active layer AT is arranged onthe first insulating layer L1. The source electrode SE and the drainelectrode DE are arranged on the active layer AT. The source electrodeSE and the drain electrode DE are spaced apart from each other. A secondinsulating layer L2 is arranged to cover the source electrode SE and thedrain electrode DE. In FIG. 8, a bottom-gate type thin-film transistorin which the gate electrode GE is arranged below the active layer AT isshown as an example. However, the present inventive concept is notlimited thereto. For example, various types of thin-film transistorssuch as a top-gate type thin-film transistor, in which the gateelectrode GE is arranged over the active layer AT, may be employed.

The active layer AT may include various materials. For example, in anexemplary embodiment, the active layer AT may include an inorganicsemiconductor material such as amorphous silicon or crystalline silicon.In an exemplary embodiment, the active layer AT may include an oxidesemiconductor. In an exemplary embodiment, the active layer AT mayinclude an organic semiconductor material.

The gate electrode GE, the source electrode SE, and the drain electrodeDE may include a single layer or multiple layers including at least onematerial selected from, for example, Al, platinum (Pt), palladium (Pd),silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd),iridium (Ir), chrome (Cr), lithium (Li), calcium (Ca), molybdenum (Mo),titanium (Ti), tungsten (W), and copper (Cu).

The first insulating layer L1 and the second insulating layer L2 mayinclude various types of insulating materials. Each of the firstinsulating layer L1 and the second insulating layer L2 may include asingle-layered structure or a multi-layered structure including one ormore insulating layers, each of the insulating layers including amaterial selected from, for example, silicon dioxide (SiO₂), siliconnitride (SiNx), silicon oxynitride (SiON), aluminum oxide (Al₂O₃),titanium dioxide (TiO₂), tantalum pentoxide (Ta₂O₅), hafnium oxide(HfO₂), zirconia ZrO₂), barium-strontium-titanate (BST), and leadzirconate titanate (PZT).

A planarization layer 250 may be further arranged above the TFT arraylayer. The pixel electrode PE is arranged on the planarization layer250. The pixel electrode PE penetrates the planarization layer 250 andthe second insulating layer L2 to be thereby connected to the drainelectrode DE of the switching device TFT. The first alignment layer AL1configured to align the liquid-crystal molecules 213 may be arranged onthe pixel electrode PE.

A light-blocking pattern BP, a color filter CF, an over-coating layerOC, and the common electrode CE are arranged over the second substrate212. In addition, a second alignment layer AL2 configured to align theliquid-crystal molecules 213 may be arranged on the common electrode CE.

The second substrate 212 may be a glass substrate or a plasticsubstrate. An external surface of the second substrate 212 is a displaysurface DS.

The light-blocking pattern BP is arranged on the second substrate 212 ina position corresponding to an area in which the switching device TFT, agate line, and data lines are arranged. The light-blocking pattern BPblocks light. It is to be understood that the position in which thelight-blocking pattern BP is arranged in FIG. 8 is exemplary, and thepresent inventive concept is not limited thereto. For example, in anexemplary embodiment, the light-blocking pattern BP may be arranged onthe first substrate 211.

The color filter CF is arranged on the second substrate 212, and filterscolor light. It is to be understood that the arrangement of the colorfilter CF illustrated in FIG. 8 is exemplary, and the present inventiveconcept is not limited thereto. For example, in an exemplary embodiment,the color filter CF may be arranged on the first substrate 211.

The over-coating layer OC is arranged over the second substrate 212 onwhich the color filter CF is arranged. The over-coating layer OCplanarizes an upper surface of the second substrate 212. In an exemplaryembodiment, the over-coating layer OC may be omitted.

The common electrode CE is arranged over the second substrate to 212 toface the pixel electrode PE. A reference voltage, that is, a commonvoltage, is applied to the common electrode CE, in which the referencevoltage defines a polarity of a voltage applied to the pixel electrodePE. In an exemplary embodiment, the common electrode CE may have a shapeof a flat plate. However, the inventive concept is not limited thereto.

The liquid-crystal layer 203 includes the liquid-crystal molecules 213.FIG. 8 shows an example in which the liquid-crystal layer 203 is avertical-alignment liquid-crystal layer. However, the present inventiveconcept is not limited thereto. For example, in an exemplary embodiment,the liquid-crystal molecules 213 may be aligned in a horizontaldirection and be shifted by about 90° between the pixel electrode PE andthe common electrode CE.

When a voltage is applied between the pixel electrode PE and the commonelectrode CE, an electric field is applied to the liquid-crystal layer203. The electric field changes the arrangement of the liquid-crystalmolecules 213 to thereby adjust an amount of light passing through theliquid-crystal layer 203 so that the light-emitting panel 200 maygenerate light.

In an exemplary embodiment, a polarization layer 270 may be arranged onthe display surface DS of the second substrate 212. In an exemplaryembodiment, the polarization layer 270 may be arranged on a flat surfaceof the planarization layer 120 (shown in FIG. 2) of the optical filter100 (shown in FIG. 2). When light is generated from the light-emittingpanel 200, the polarization layer 270 may have the light incident on theoptical filter 100 (shown in FIG. 2) in a polarized state. When thepolarization layer 270 is arranged on a second surface of the substrate110 (shown in FIG. 2), the polarization layer 270 polarizes light havingpassed through the optical filter 100 (shown in FIG. 2). In this case,as the light passes through the optical filter 100 (shown in FIG. 2),since scattering, etc. occurs, it may be difficult to generate accuratepolarization by using the polarization layer 270. Accordingly, thepolarization layer 270 may be arranged between the light-emitting panel200 and the optical filter 100 (shown in FIG. 2).

According to exemplary embodiments of the present inventive concept, adisplay device may increase utilization of incident light by decreasingincident light that may not excite quantum dots (e.g., incident lightthat is filtered out), to thereby improve color reproducibility andlight efficiency.

It should be understood that the exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exemplaryembodiment should typically be considered as available for other similarfeatures or aspects in other exemplary embodiments.

While the present inventive concept has been particularly shown anddescribed with reference to the exemplary embodiments thereof, it willbe understood by those of ordinary skill in the art that various changesin form and detail may be made therein without departing from the spiritand scope of the present inventive concept as defined by the followingclaims.

What is claimed is:
 1. An optical filter, comprising: a substratecomprising a plurality of pixel areas spaced apart from each other and alight-blocking area arranged between the plurality of pixel areas; aplurality of color filters arranged on a first surface of the substrateand corresponding to the plurality of pixel areas; a plurality ofconversion layers arranged on the first surface of the substrate andcorresponding to the plurality of color filters, wherein each of theconversion layers comprises at least one inclined side surface; and areflective layer arranged on the at least one inclined side surface ofeach of the plurality of conversion layers, wherein the reflective layerextends to the light-blocking area and is arranged consecutively on twoadjacent inclined side surfaces from among the inclined side surfaces ofthe plurality of conversion layers and the light-blocking area betweenthe two adjacent inclined side surfaces.
 2. The optical filter of claim1, wherein a horizontal cross-sectional area of at least one of theplurality of conversion layers decreases in a direction away from thesubstrate.
 3. The optical filter of claim 1, wherein the color filtersare spaced apart from each other, and the reflective layer extends to aportion between two neighboring color filters from among the pluralityof color filters.
 4. The optical filter of claim 3, wherein thereflective layer is arranged between side surfaces of the twoneighboring color filters.
 5. The optical filter of claim 1, wherein theplurality of color filters extends to the light-blocking area such thatside surfaces of the plurality of color filters are in contact with eachother.
 6. The optical filter of claim 1, wherein the plurality of colorfilters comprises: a first color filter; a second color filter; and athird color filter, wherein each of the color filters transmits light ofa different color, and the first color filter, the second color filter,and the third color filter overlap each other in the light-blocking areato form a partition wall.
 7. The optical filter of claim 6, wherein thepartition wall comprises an inclined surface, and the plurality ofconversion layers is arranged in concave portions defined by thepartition wall.
 8. The optical filter of claim 7, wherein the reflectivelayer covers an upper surface of the partition wall.
 9. The opticalfilter of claim 1, further comprising: a planarization layer providing aflat surface by covering the plurality of conversion layers.
 10. Theoptical filter of claim 1, wherein the plurality of conversion layerscomprises: a first conversion layer; a second conversion layer; and athird conversion layer, wherein each of the conversion layers comprisesscattering particles, the first conversion layer further comprises firstquantum dots, and the second conversion layer further comprises secondquantum dots, and the first quantum dots and the second quantum dotscomprise a same material and have different sizes.
 11. A display device,comprising: a light-emitting panel configured to emit incident light ofa single color; and an optical filter configured to convert the incidentlight into light of different colors, wherein the optical filtercomprises: a substrate comprising a plurality of pixel areas spacedapart from each other and a light-blocking area arranged between theplurality of pixel areas; a plurality of color filters arranged on afirst surface of the substrate and corresponding to the plurality ofpixel areas, wherein the first surface of the substrate faces thelight-emitting panel; a plurality of conversion layers arranged on thefirst surface of the substrate and corresponding to the plurality ofcolor filters, wherein the incident light is incident on the pluralityof conversion layers; and a reflective layer arranged on side surfacesof the plurality of conversion layers, wherein the reflective layerextends to the light-blocking area and is arranged integrally on theside surfaces of the plurality of conversion layers and in thelight-blocking area between the plurality of conversion layers.
 12. Thedisplay device of claim 11, wherein the light-emitting panel comprises:a plurality of light-emitting devices configured to generate theincident light of a single color, wherein the light-emitting devices arearranged to correspond to the plurality of pixel areas.
 13. The displaydevice of claim 11, wherein the light-emitting panel comprises aliquid-crystal layer comprising a plurality of liquid-crystal molecules,and the optical filter further comprises a planarization layer providinga flat surface by covering the plurality of conversion layers, whereinthe display device further comprises a polarization layer arrangedbetween the light-emitting panel and the planarization layer.
 14. Thedisplay device of claim 11, wherein each of the plurality of conversionlayers comprises an inclined side surface, and horizontalcross-sectional areas of the plurality of conversion layers decrease ina direction away from the substrate.
 15. The display device of claim 11,wherein the color filters are spaced apart from each other, and thereflective layer is arranged between side surfaces of two neighboringcolor filters from among the plurality of color filters in thelight-blocking area.
 16. The display device of claim 11, wherein theplurality of color filters comprises: a first color filter; a secondcolor filter; and a third color filter, wherein each of the colorfilters transmits light of a different color, the first color filter,the second color filter, and the third color filter overlap each otherin the light-blocking area to form a partition wall, and the pluralityof conversion layers is arranged in a concave portion defined by thepartition wall.
 17. The display device of claim 16, wherein thereflective layer covers an upper surface of the partition wall, whereinthe upper surface of the partition wall faces the light-emitting panel.18. The display device of claim 11, wherein the plurality of conversionlayers comprises: a first conversion layer; a second conversion layer;and a third conversion layer, wherein each of the conversion layerscomprises scattering particles, the first conversion layer furthercomprises first quantum dots, and the second conversion layer furthercomprises second quantum dots, and the first quantum dots and the secondquantum dots comprise a same material and have different sizes.
 19. Thedisplay device of claim 18, wherein colors of light that passes throughthe first conversion layer, the second conversion layer, and the thirdconversion layer are different from each other, and the color of thelight that passes through the third conversion layer is identical to acolor of the incident light.
 20. The display device of claim 11, furthercomprising: a low refractive index layer arranged between the pluralityof color filters and the plurality of conversion layers, and having arefractive index equal to or less than about 1.2.